https://doi.org/10.1007/s100530050077
Amplification of atomic L-R asymmetries by stimulated emission: experimental demonstration of sensitivity enhancement valuable for parity violation measurements
Laboratoire Kastler Brossel (Laboratoire
de l'Université Pierre et Marie Curie et de l'ENS,
associé au CNRS (URA 18)) ,
Département de Physique de l'École Normale Supérieure,
24 rue Lhomond, 75231 Paris Cedex 05, France
Corresponding author: a marianne@physique.ens.fr
Received:
8
October
1997
Accepted:
21
November
1997
Published online: 15 February 1998
While all Atomic Parity Violation experiments on highly forbidden transitions in a
Stark field have used the detection of fluorescence signals, our group is engaged in an
experiment on the cesium transition that uses a pump-probe scheme. The role of the probe
beam is to detect the 7S state by stimulated emission. The detected Left-Right asymmetry
(ALR) appears directly on the transmitted probe beam and the technique relies on
differential-mode atomic polarimetry. We present here experimental results which illustrate two
essential features of this approach. First, ALR is amplified when the optical thickness for
the probe beam is increased, hence it is an increasing function of the Stark field.
Secondly, the experimental sensitivity to ALR is simultaneously increased,
as demonstrated by our measurements of the signal-to-noise ratio. We emphasize also
the advantage of choosing a probe transition that involves a “dark” state: the ALR
amplification is preserved at high levels of the probe intensity because saturation effects are
greatly reduced.
PACS: 32.80.+a – Other topics in atomic properties and interactions of atoms and ions with photons / 07.60.Fs – Polarimeters and ellipsometers / 12.20.Fv – Experimental tests
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998